tbuckley/cabot-search huggingface dataset:
CSIG-31. T-TYPE CALCIUM CHANNEL BLOCKERS INDUCE METABOLIC ALTERATIONS AND APOPTOSIS IN MEDULLOBLASTOMA CELLS
Authors: Mohammed Sedeeq, Ahmed Maklad, Zikai Feng, Taush Dutta, Richard Wilson, Nuri Guven, Iman Azimi
Journal: Neuro-Oncology (2022)

Abstract Medulloblastoma (MB) is the most common malignant paediatric brain tumour. In our previous studies, in a screen of a panel of calcium channel modulators in our novel high-throughput 3D assay, we identified T-type (CaV3) channel inhibitors, mibefradil and NNC-55-0396 (NNC) as selective inhibitors of MB cell growth. Mibefradil was originally approved for the treatment of hypertension and angina pectoris, and recently successfully completed a Phase-I trial for recurrent high-grade glioma. NNC is an analogue of mibefradil with multiple advantages compared to mibefradil that makes it attractive for potential future clinical trials. T-type channels have a unique low voltage-dependent activation/inactivation, and many studies suggest that they have a direct regulatory role in controlling Ca2+ signalling in non-excitable tissues, including cancers. In this study, we characterized the effect of mibefradil and NNC on MB cells and elucidated their mechanism of action. This study demonstrates that the induction of toxicity in MB cells is selective to T-type but not to L-type Ca2+ channel inhibitors. Addition of CaV3 inhibitors to vincristine sensitised MB cells to this MB chemotherapeutic agent, suggesting an additive effect. Furthermore, CaV3 inhibitors induced cell death in MB cells via apoptosis. Supported by proteomics data and cellular assays, apoptotic cell death was associated with reduced mitochondrial membrane potential and reduced ATP levels, which suggests that both compounds alter the metabolism of MB cells. We also identified that CACNA1H (encoding the CaV3.2 protein) is significantly upregulated in aggressive Groups 3 and 4 MB patient samples, and its higher expression is associated with higher metastasis and lower patient survival rates. This study offers new insights into the action of mibefradil and NNC and will pave the way to test these molecules or their analogues in pre-clinical MB models alone and in combination with vincristine to assess their suitability as a potential MB therapy.
QOL-11. COMMUNICATION IN THE CONTEXT OF GLIOBLASTOMA TREATMENT: WHAT MATTERS MOST
Authors: Florien Boele, Sean Butler, Emma Nicklin, Lucy Pointon, Susan Short, Louise Murray
Journal: Neuro-Oncology (2022)

Abstract BACKGROUND Given the poor prognosis of glioblastoma, it is critical that the benefits and burdens of treatments are clearly discussed with patients and family caregivers. We investigated experiences and preferences around glioblastoma treatment communication in patients, caregivers, and healthcare professionals (HCPs). METHODS Semi-structured qualitative interviews were conducted with adult glioblastoma patients, their caregivers, and HCPs. Purposive sampling was used to capture views across the entire disease trajectory and different specialties. Interviews were recorded, transcribed verbatim, and analysed thematically. RESULTS In total, 15 patients, 13 caregivers (in N=12 individual and N=8 dyadic interviews), and five HCPs participated (N=5 individual interviews). Four main themes were identified. 1) Communication practice and preferences. Risks and side-effects of anti-tumour treatments were explained clearly, with information layered and revisited frequently to aid understanding. Treatment was often understood to be ‘the only option’, particularly at recurrence. Understanding the impact of side-effects on daily life could be enhanced, including those from supportive medication (e.g., corticosteroids); alongside more proactive communication about support services. 2) What matters most. Patients/caregivers valued being well-supported by a trusted treatment team, feeling involved, having a sense of control, and quality of life. HCPs similarly highlighted trust, maintaining independence and quality of life, and emotional support as key. 3) Decision-making. With limited treatment options, trust and control are crucial in decision-making among patients, caregivers, and HCPs. While patients ultimately prefer to follow HCP advice they want to be involved, consider all alternatives, and voice what matters to them. 4) Impact of Covid-19. During the pandemic, greater efforts to maintain good communication were necessary. While negative impacts of Covid-19 were limited, caregivers appeared most disadvantaged by pandemic-related restrictions (e.g., limited visiting). DISCUSSION In glioblastoma treatment communication, building trusting relationships, maintaining a sense of control, and good support are identified by patients, caregivers, and HCPs as critical.
BIOS-05. SANGER SEQUENCING AND COPY-NUMBER ALTERATION ANALYSIS WITH MLPA CAN CLINICALLY CLASSIFY IDH-WILD-TYPE LOWER-GRADE ASTROCYTOMA
Authors: Yoshiki Arakawa, Yasuhide Makino, Ema Yoshioka, Tomoko Shofuda, Takeshi Kawauchi, Yukinori Terada, Masahiro Tanji, Daisuke Kanematsu, Yohei Mineharu, Susumu Miyamoto, Yonehiro Kanemura
Journal: Neuro-Oncology (2022)

Abstract The IDH-wild-type lower-grade astrocytomas are a heterogeneous entity. According to 2021 WHO classification, IDH-wild-type astrocytomas with any of the following factors show poor prognosis: combination of chromosome 7 gain and 10 loss (+7/-10), and/or EGFR amplification, and/or TERT promoter (TERTp) mutation. Multiplex ligation-dependent probe amplification (MLPA) can detect copy number alterations with a reasonable cost. The purpose of this study was to find precise and cost-effective method for stratifying the prognosis of IDH-wild-type astrocytomas. Sanger sequencing, MLPA, and quantitative methylation-specific PCR were performed for 42 IDH-wild-type lower-grade astrocytomas surgically treated at Kyoto University Hospital, and overall survival was analyzed for 40 patients. Of the 42 IDH-wild-type astrocytomas, 21 were classified as grade 4 in 2021 WHO classification and all of them had either TERTp mutation or EGFR amplification. Kaplan-Meier analysis confirmed the prognostic significance of 2021 WHO Classification, and WHO grade was also prognostic. Cox regression hazard model identified PTEN loss and PDGFRA amplification as independent significant prognostic indicators (Risk ratio of 9.75, p&amp;lt; 0.001 and 13.9, p=0.002). The classification recommended by 2021 WHO Classification could be completed using Sanger sequencing and MLPA. Survival analysis revealed PTEN and PDGFRA were significant prognostic factors for IDH-wild-type lower-grade astrocytomas.
NIMG-26. UPTAKE OF [18F]GE-180 IN TSPO PET IS ASSOCIATED WITH SURVIVAL IN PATIENTS WITH RECURRENT GLIOMA
Authors: Stefanie Quach, Adrien Holzgreve, Lena Kaiser, Marcus Unterrainer, Franziska Dekorsy, Debie V Nelwan, Laura Bartos, Sabrina Kirchleitner, Jonathan Weller, Lorraine Weidner, Maximilian Niyazi, Victoria Ruf, Jochen Herms, Sophia Stöcklein, Christian Wetzel, Markus J Riemenschneider, Louisa von Baumgarten, Niklas Thon, Matthias Brendel, Rainer Rupprecht, Peter Bartenstein, Joerg-Christian Tonn, Nathalie Albert
Journal: Neuro-Oncology (2022)

Abstract OBJECTIVE The 18 kDa translocator protein (TSPO) is expressed in both activated microglia and glioma cells. Elevated expression of TSPO has been reported to be associated with higher WHO grade. Here we analyze whether TSPO positron emission tomography (PET) signal using the tracer [18F]GE-180 is correlated with clinical outcome in a cohort of patients with recurrent glioma. METHODS Patients with suspected glioma recurrence received a [18F]GE-180 TSPO PET. All recurrent tumors were confirmed either by stereotactic biopsy or resection. Maximum standard uptake value SUVmax as well as tumor volume in MRI and, if available, in [18F]FET PET were evaluated together with patient characteristics (age, sex, Karnofsky-Performance score) and neuropathological features (WHO grade, IDH-mutation status). Uni- and multivariate Cox regression and Kaplan-Meier survival analyses were performed to identify prognostic factors for post-recurrence survival (PRS) and time to treatment failure (TTF). RESULTS 88 consecutive patients were evaluated. TSPO tracer uptake correlated with tumor grade at recurrence (p&amp;lt; 0.05), with no significant differences between IDH-wildtype and IDH-mutant tumors. Within the subgroup of IDH-mutant glioma (n= 46), patients with low SUVmax (median split, ≤ 1.60) had a significantly longer PRS (median 41.6 vs. 25.3 months, p= 0.031) and TTF (32.2 vs 8.7 months, p= 0.001). Also among IDH-wildtype tumors (n= 42), patients with low SUVmax (≤ 1.89) had a significantly longer PRS (median not reached vs 8.2 months, p= 0.002). SUVmax remained an independent prognostic factor for PRS in a multivariate analysis including WHO grade, IDH status and age. Tumor volume defined by [18F]FET PET or contrast-enhanced MRI correlated weakly with TSPO tracer uptake. Treatment regimen did not differ between the subgroups. CONCLUSION Our data suggest that uptake of [18F]GE-180 in TSPO PET can add prognostic information in patients with recurrent glioma even in molecular defined subgroups and might serve as an imaging biomarker.
CCRG-04. TARGETING THE CELL-CYCLE EFFECTS OF TUMOR TREATING FIELDS (TTFIELDS) TO INCREASE ITS EFFICACY
Authors: Paul Slangen, Basma Elbakary, Lotte van Mil, Mark de Gooijer, Lenno Krenning, Bram van den Broek, Marjolijn Mertz, Olaf Van Tellingen, Gerben Borst
Journal: Neuro-Oncology (2022)

Abstract Tumor Treating Fields (TTFields) are a novel, non-invasive FDA-approved treatment modality for glioblastoma (GBM) that utilises alternating electric fields. Our research aims to elucidate the effect of TTFields on the cell cycle to advance the understanding of TTFields and find novel targets for increasing its efficacy. We studied the cell cycle progression using live-cell imaging (inovitro Live™) of PIP-FUCCI-transduced GBM cells, EdU incorporation, RPA foci and fiber assay (in U251-MG, SNB-19, A172). These tools allow us to track individual cells evaluate the time spent in each cell cycle phase, and study the ultimate cell fate in control and treatment conditions concerning the cell cycle and replication fork dynamics. Statistical testing was performed by 2-way ANOVA, Tukey-corrected for multiple comparisons, and Kruskal-Wallis test. TTFields causes an immediate delay in S and G2 cell cycle phase, with a subsequent G1 arrest. Wee1 inhibition by AZD1775 forces cells through S-phase and abrogates the subsequent TTFields-induced G2-checkpoint, preventing DNA repair. Combined treatment with TTFields and AZD1775 led to decreased incorporation of EdU and an increase in S-phase-specific phospho-RPA foci. TTFields reduced significantly the DNA fiber length after 12, 24, 48 and 72 hrs of exposure (10.2, 8.3, 7.1 and 5.6 vs 13 um), with also an increase in replication fork asymmetry at these time points (0.56, 0.45, 0.49, and 0.47 vs 0.9 ratio) respectively. CombiningTTFields with either Wee1, ATR, or Chk1 inhibition synergistically decreased clonogenic survival. TTFields induced cell cycle effects with the induction of replication stress, which is aggravated by inhibition of Wee1. Additionally, Wee1, ATR, and Chk1 inhibition dramatically boost the efficacy of TTFields in vitro. This combination strategy has promising clinical potential and will be tested in vivo in different GBM xenografts. Cell signaling and signaling pathways
CNSC-09. THE NEUROENDOCRINE FACTOR VGF IS NECESSARY FOR THE MAINTENANCE OF THE TUMOR STEM CELL POPULATION IN GLIOBLASTOMA
Authors: Somanath Kundu, Abigail Venskus, Lee Quiruz, John Longo, Sharon Longo, Jamie Walker, Timothy Richardson, Mariano Viapiano
Journal: Neuro-Oncology (2022)

Abstract A major factor that contributes to the unchecked growth and recurrence of glioblastoma (GBM) tumors is the presence of a heterogeneous population of GBM stem-like cells (GSCs) that continuously replenish the tumor mass. Targeting strategies against this key cell population have rarely considered the trophic signals from peritumoral neural cells, which can protect the tumor cells during therapy and therefore promote recurrence. Here, we have focused on the little-known secreted factor VGF and its derived neuropeptides, which are largely restricted to the CNS and mediate paracrine communication between neural cells. We analyzed over 200 tissue specimens and cultured GBM cells, demonstrating that VGF is upregulated in malignant gliomas and expressed in GSCs of different subtypes, although it is markedly reduced in differentiated GBM cells. More importantly, we detected VGF expression in peritumoral astrocytes, even though this neuroendocrine factor has never been described in glial cells in normal brain. Co-culture experiments and scRNAseq data from clinical tumors confirmed that VGF is expressed in tumor-associated astrocytes, suggesting that these cells are a paracrine source of VGF in GBM. Accordingly, purified exogenous VGF increased the proliferation of GSCs and rescued GSC viability when the tumor cells were treated with the chemotherapeutic temozolomide. Moreover, purified VGF decreased the expression of inflammatory cytokines in activated macrophages, suggesting that this factor may also contribute to local immunosuppression in gliomas. Conversely, knockdown of VGF in GSCs was sufficient to decrease their viability, self-renewal, and expression of stemness-related genes. At the molecular level, VGF increased intracellular calcium and Akt/mTOR signaling in GSCs, suggesting a possible G protein coupled receptor-mediated mechanism of action. Taken together, our results explore for the first time the role of brain-derived VGF in GBM progression, highlighting the importance of disrupting the communication between the tumor and its microenvironment to achieve long-term anti-tumor efficacy.
EXTH-41. COMBINED PHARMACOLOGICAL AND GENETIC SCREENING TO IDENTIFY DEPENDENCIES AND COMBINATIONS IN ACVR1-MUTANT DIFFUSE MIDLINE GLIOMA
Authors: Rebecca Rogers, Diana Carvalho, Yura Grabovska, Elisabet Fernandez, Elisa Izquierdo, Alan Mackay, Chris Jones
Journal: Neuro-Oncology (2022)

Abstract Somatic mutations in ACVR1, which encodes the serine/threonine kinase ALK2, are found in 20-25% of DMG-H3K27 patients. Treatment of ACVR1-mutant patient-derived models with multiple chemotypes of ALK2 inhibitors (ALK2i) results in reduced cell viability in vitro and extended survival in orthotopic xenografts in vivo but, as single agents, these inhibitors were unable to achieve a complete anti-tumour response. Recently we reported that combinatorial treatment of ACVR1-mutant DIPG cells with vandetanib (RTK inhibitor) and everolimus (mTOR/ABC transporter inhibitor) was synergistic both in vitro and in vivo and was shown to be a feasible combination to trial clinically in this setting. To identify specific dependencies in ACVR1-mutant cells which may be translatable with novel synergistic drug combinations alongside ALK2i, we have implemented both candidate and unbiased drug and genetic screening approaches. Using a panel of 13 patient-derived ACVR1-mutant models (and 6 wild-type controls), we identified synergy between multiple chemotypes of ALK2i (M4K2009/LDN-214117) and PI3K/mTOR (AZD8055/everolimus) and MEK inhibitors (trametinib), reflecting the common co-segregation of PIK3CA/PIK3R1 alterations in these tumours. Whole-genome CRISPR/Cas9 screening of ACVR1-mutant SU-DIPG-IV cells in combination with two ALK2i (M4K2009/LDN-193189), confirmed a specific MTOR genetic dependency, as well as for the protein phosphatase regulatory subunit PPP2R1A, known to play a role in MAPK pathway activation. Additional hits include the serine/threonine kinase PKMYT1, a negative regulator of the G2/M checkpoint via a functionally redundant phosphorylation of CDK1/CCNB1 alongside WEE1; confirmatory drug assays with the WEE1 inhibitor AZD1775 resulted in a synergistic interaction with ALK2i in ACVR1-mutant cells. Hits were integrated with DepMap using ‘gene effect’ scores (Chronos) enabling filtering of common essential genes. Preliminary pathway enrichment analysis (MAGeCKFlute) identified ALK2i-specific vulnerabilities involving TGFB1/SMAD signalling and histone deacetylation. These data highlight functionally rational and novel combinatorial possibilities for children with ACVR1-mutant DMG, with systematic preclinical assessment required for prioritisation for the clinic.
EXTH-94. LOCALIZED INTRATUMORAL TREATMENT WITH ADOPTIVE T CELL THERAPY FOLLOWED BY ONCOLYTIC ADENOVIRUS DELTA-24-RGDOX INDUCES SUSTAINABLE REGRESSION OF DISSEMINATED SOLID TUMORS THROUGH ANTIGEN SPREAD
Authors: Hong Jiang, Dong Ho Shin, Yanhua Yi, Xuejun Fan, Joy Gumin, Andrew Gillard, Marta M Alonso, Frederick Lang, Candelaria Gomez-Manzano, Juan Fueyo
Journal: Neuro-Oncology (2022)

Abstract Tumor-targeting biological therapies, including adoptive T cell therapy (ACT) and oncolytic viruses, are being tested clinically to address the challenges in treating advanced solid tumors with heterogeneity and immune suppressive microenvironment (TME). Since complementary properties of these two approaches have been observed, we hypothesize that localized intratumoral treatment with combination of ACT and Delta-24-RGDOX (third generation oncolytic adenovirus developed by our group) induces not only potent therapeutic effect in treated tumor but also abscopal benefit to eliminate distant disseminated tumors. Using a B16-C57BL/6 melanoma model with disseminated tumors in C57BL/6 mice, we found gp100-specific CD8+ T cells injected into the first subcutaneous (s.c.) tumor showed tropism for distant s.c. and intracranial tumors, tumor draining lymph nodes, compared to spleen, blood and normal brain hemisphere. In a B16-OVA-C57BL/6 s.c./s.c. tumor model, Delta-24-RGDOX injections following gp100-specific T cells in the first tumor increased total cytotoxic T cell presence within both tumors, including gp100- and OVA- specific T cells. Further analysis revealed that Delta-24-RGDOX reduced the exhaustion of OVA-specific T cells while that of gp100-specific T cells kept at a low level. Moreover, Delta-24-RGDOX augmented the activity of the splenocytes against the tumor cells and other tumor-associated antigens (OVA, TRP2) than gp100. Consequentially, the combination of OVA-specific T cells and Delta-24-RGDOX was more potent to inhibit the injected and untreated distant tumor growth and caused improved survival rate than either of the agent alone (p &amp;lt; 0.05). Importantly, we observed relapse of the regressed tumors in the T cell treatment group, but not in the combination group. The survivors developed immune memory against rechallenging with B16-OVA cells. Collectively, our data demonstrate that localized treatment with intratumoral ACT followed by Delta-24-RGDOX induces global immune activation and antigen spread to expand antitumor T cell repertoire, leading to efficacious systemic anti-tumor immunity and sustainable tumor regression.
NIMG-46. TOWARDS PREDICTING TUMOR AGGRESSIVENESS WITH RADIOPATHOMIC ANALYSIS OF MULTI-PARAMETRIC ANATOMICAL, DIFFUSION-WEIGHTED, AND METABOLIC MRI IN PATIENTS WITH NEWLY-DIAGNOSED GLIOMAS
Authors: Oluwaseun Adegbite, Nate Tran, Annette Molinaro, Joanna J Phillips, Jacob Ellison, Yan Li, Tracy Luks, Anny Shai, Devika Nair, Valentina Pedoia, Javier Villanueva-Meyer, Mitchel S Berger, Shawn L Hervey-Jumper, Manish Aghi, Janine Lupo
Journal: Neuro-Oncology (2022)

Abstract INTRODUCTION Pathologically aggressive tumor biology can extend beyond the contrast-enhancing or non-enhancing anatomical lesions in patients with glioma. Identification of malignant regions can help guide diagnosis and subsequent treatment planning. This study leverages a unique multi-parametric MRI dataset with tissue samples of known spatial coordinates to noninvasively predict cellular proliferation (KI-67) and a novel index of tumor aggressiveness (TAI), that combines proliferation, cellularity, and tumor-score. METHODS 420 tissue samples were collected from 162 patients with newly-diagnosed glioma (47% IDH-wildtype). Clinical imaging consisted of T2-weighted, T2-FLAIR, T1-weighted pre- and post-contrast images, and apparent diffusion coefficient (ADC) and fractional anisotropy (FA) from diffusion-weighted imaging. Mean normalized imaging metrics were quantified from 5mm spheres centered at the location of the tissue sample. A single spectrum was reconstructed at the location of each tissue sample from 3D 1H-MR Spectroscopic Imaging (MRSI) before quantifying normalized metabolite peak-heights for choline, creatine, NAA, lactate/lipid, and relative indices. Univariate mixed-effects linear regression models were employed and features with p&amp;lt; 0.2 were selected for subsequent model building. Support vector machine (SVM), random forest, and gradient boosting machine-learning algorithms were trained and tested on a ⅔-⅓ train-test split with 4-fold cross-validation in training to predict a high/low KI-67 and TAI. RESULTS Although none of the individual imaging metrics were significantly associated with KI-67 in the univariate analysis, all diffusion and several MRSI metrics (ncholine, nNAA, CNI, excess choline and creatine) were significantly associated with cellularity. Preliminary multivariate analyses to date suggest that the best radiopathomic model performance is achieved when an SVM was used along with T1-precontrast, nADC, and all metabolite levels (mean cross-validation AUC=0.73 and accuracy=.77). CONCLUSION Our results suggest that multi-parametric physiologic and metabolic MRI are useful for radiopathomic-mapping of tumor aggressiveness and are currently being optimized in a larger cohort.
EXTH-53. IL-12 ARMORED CAR T CELL THERAPY FOR HETEROGENEOUS GLIOBLASTOMA
Authors: Steven Shen, Sarah Cook, Carter Suryadevara, Kelly Hotchkiss, David Snyder, Luis Sanchez-Perez, John Sampson
Journal: Neuro-Oncology (2022)

Abstract INTRODUCTION Chimeric antigen receptor (CAR) T cells specific for the glioblastoma (GBM)-specific epidermal growth factor receptor variant III (EGFRvIII; CARvIII) have successfully treated tumors homogeneously expressing EGFRvIII when combined with lymphodepletion, however this is not recapitulated clinically. We generated an “armored” CARvIII which constitutively secretes IL-12, a stimulatory cytokine that enhances T cell persistence and function, that is capable of treating orthotopic heterogeneous GBM in immune competent mice. METHODS C57Bl/6 mice were intracranially (IC) implanted with 5 x 105 of either homogenous (CT2AvIII) or heterogeneous (1:1 CT2AvIII and CT2A parental) tumor cells. Mice were treated with 2 x 106 CARvIII or IL-12 CARvIII seven days post tumor implant and monitored for survival. TCRα -/-, CD8-/- and C57Bl/6 mice were IC implanted with homogeneous or heterogeneous tumors and treated 7 days post implant with intracranial IL-12 CARvIII therapy to assess the role of endogenous T cells. T cells within the tumor microenvironment were characterized by flow cytometry days 8, 14, and 17 post tumor implantation. RESULTS IL-12 CARvIII cells were successfully generated, secreted IL-12, and were cytotoxic against EGFRvIII-expressing tumor cells in vitro. IL-12 CARvIII therapy was curative in homogenous CT2AvIII tumors (p&amp;lt; 0.0001) and conferred a long-term survival in 50% of mice with heterogeneous CT2AvIII:CT2A parental tumors in vivo (p&amp;lt; 0.0001). Furthermore, IL-12 CARvIII therapy successfully eradicated the homogeneous CT2AvIII tumors in TCRα -/- and CD8-/- mice but failed to produce any efficacy against the heterogeneous CT2AvIII:CT2A parental tumors (p=0.0002). Endogenous T cells in IL-12 CARvIII treated mice were found to be more migratory, and interestingly more exhausted than in CARvIII treated mice. CONCLUSIONS Our findings show that IL-12 CARvIII can effectively eradicate IC homogenous tumors without lymphodepletion. Surprisingly, IL12 CARvIII therapy also treated IC heterogeneous glioma. Heterogeneous tumor clearance required an endogenous CD8 T cell response.